Suppression of tiller bud activity in tillering dwarf mutants of rice [Oryza sativa]

• Published in: Plant and cell physiology Vol. 46; no. 1; pp. 79 - 86
• Main Authors: Ishikawa, S.(Tokyo Univ. (Japan)), Maekawa, M, Arite, T, Onishi, K, Takamure, I, Kyozuka, J
• Format: Journal Article
• Language: English
• Published: Japan Oxford University Press 01-01-2005; Oxford Publishing Limited (England)
• Subjects: Amino Acid Sequence; Arabidopsis - genetics; Arabidopsis - growth & development; Base Sequence; BOURGEON; BUDS; Chromosome Mapping; CONTROL GENETICO; DNA, Plant - genetics; DORMANCE; DORMANCY; DORMICION; DWARFS; ENANO; Genes, Plant; GENETIC CONTROL; Keywords: Axillary meristem — Bud activity — Bud dormancy — Rice — Tiller; leucine-rich region; LLR; LUTTE GENETIQUE; MACOLLAMIENTO; Meristem - anatomy & histology; Meristem - growth & development; Molecular Sequence Data; MUTANT; MUTANTES; MUTANTS; Mutation; NAIN; Oryza - anatomy & histology; Oryza - genetics; Oryza - growth & development; ORYZA SATIVA; Phenotype; Plant Proteins - genetics; reverse transcriptase–polymerase cahin reaction; RT–PCR; SAM; Sequence Homology, Amino Acid; shoot apical meristem; TALLAGE; TILLERING; VARIEDADES; VARIETE; VARIETIES; YEMA (PLANTA)
• ISSN: 0032-0781; 1471-9053
• DOI: 10.1093/pcp/pci022

In this study, we analyzed five tillering dwarf mutants that exhibit reduction of plant stature and an increase in tiller numbers. We show that, in the mutants, axillary meristems are normally established but the suppression of tiller bud activity is weakened. The phenotypes of tillering dwarf mutants suggest that they play roles in the control of tiller bud dormancy to suppress bud activity. However, tillering dwarf mutants show the dependence of both node position and planting density on their growth, which implies that the functions of tillering dwarf genes are independent of the developmental and environmental control of bud activity. Map-based cloning of the D3 gene revealed that it encodes an F-box leucine-trich repeat (LRR) protein orthologous to Arabidopsis MAX2/ORE9. This indicates the conservation of mechanisms controlling axillary bud activity between monocots and eudicots. We suggest that tillering dwarf mutants are suitable for the study of bud activity control in rice and believe that future molecular and genetic studies using them may enable significant progress in understanding the control of tillering and shoot branching.